As part of a population-based prospective birth cohort study in the Netherlands, it was learned that exclusive breast-feeding for the first three months of life didn’t change children’s risk of becoming overweight by age 5 to 6 years. The results, which were published in the Archives of Disease in Childhood, join a body of sometimes contradictory findings on breast-feeding and the risk for obesity.

The head of the study, Esmee van der Willik, writes that the prevalence of childhood obesity has increased substantially in the last decades. Although its presence in more developed countries seems to be plateauing, obesity in children remains a major cause of adverse health consequences such as cardiovascular disease, asthma and type 2 diabetes. Psychological and social problems could also occur, such as lower self-esteem, depression, discrimination and stigmatization.

Of course, obesity is never an issue that can be completely resolves, since it will always look different in different populations. The Netherlands tends to have a higher income level, more homogenous ethnic makeup and a higher incidence of breast-feeding than in the US. The Dutch study involved 3,367 children that were part of a larger population-based child health study and were singletons without congenital malformations, which can affect growth patterns. The researchers excluded 2,776 children whose feeding type or weight status were unknown.

Children who were overweight at age 6 months were four times more likely than their thinner peers to be overweight at the 5- to 6-year mark, regardless of feeding type. Of the babies in the study, 42.3% were exclusively breast-fed for at least 3 months. At 6 months, 11.4% of those babies were overweight, statistically indistinguishable from the 12.6% of formula-fed or mixed-fed infants who were overweight at that age. By 5 to 6 years old, overweight children made up 10.1% of those who had been breast-fed, as well as 11.2% of those in the formula or mixed feeding groups, once again not statistically significant. There remained no association after adjusting for confounding factors such as maternal BMI, smoking during pregnancy, ethnicity and birth weight.